NYPD’s gunfire detection system accurate just 13% of the time: comptroller

A scathing report from city Comptroller Brad Lander found that ShotSpotter, the NYPD’s highly touted gunfire location system, accurately identifies shootings only about 13% of the time.

The report issued Thursday concludes that inaccurate identifications of gunfire eat up police resources at a time when the NYPD is already strapped for personnel.

“ShotSpotter claims to be ‘a proven detection system’ that is ‘faster and more accurate’, but our audit found that 87% of the time, ShotSpotter is sending NYPD officers in response to loud noises that don’t turn out to be confirmed shootings,” said Lander, a possible candidate to challenge Mayor Adams in the next election.

“The evidence shows that NYPD is wasting precious time and money on this technology.”

The NYPD has been using SpotSpotter since 2015 and spent more than $45 million on the system. The company that developed the technology is now known as SoundThinking. Former two-time NYPD Commissioner Bill Bratton is on the company’s board of directors.

“Loss of the ShotSpotter program would result in a less safe working environment for officers and an increased chance of violent encounters for all New Yorkers,” the NYPD said in a written response to the audit.

A police spokesman added, “The department consistently reviews the effectiveness of technologies it utilizes to combat crime. ShotSpotter remains an integral tool in the NYPD’s mission of addressing gun violence and keeping the public safe.”

SoundThinking stated it is reviewing the report but called it “gravely misinformed in its assessment of data and the value of ShotSpotter as a critical public safety tool,” insisting the tech “is both accurate and effective.”

“For example, assuming that the lack of confirmation of a shooting automatically means that some other loud event triggered a false alert is erroneous and a perilous assumption,” SoundThinking spokesman Jerome Filip said in part in a statement.

The report said the system uses more than 2,000 sensors arrayed around the city, mainly in higher-crime areas to locate suspected gunfire.

ShotSpotter alerts are considered “confirmed” as shooting incidents when NYPD recovers evidence like guns, bullet fragments or shell casings or video, or there are eyewitnesses, victims shot, summary arrests or 911 calls that report a shooting, the report said.

The comptroller’s report claims the city’s contract with SoundThinking requires the system to report at least 90% of “probable” gunshots, giving the company an incentive to “overreport” loud noises as gunshots.

The audit covered eight months spanning 2022 and 2023 and found that “unconfirmed” shootings totaled between 80% and 92% of all ShotSpotter alerts, meaning that cops were sent to 7,262 incidents that did not turn out to be shootings.

“This translates to thousands of hours of officer time responding to ShotSpotter alerts that do not turn out to be confirmed shootings,” the audit stated.

Just in June 2023, out of 940 ShotSpotter alerts, 771, or 82%, could not be confirmed as shootings at the scene; 47, or 5%, were unfounded; and 122, or 13%, were confirmed as shootings, the audit found. NYPD officers spent 427 hours investigating those alerts not confirmed as shootings.

While the NYPD has said ShotSpotter reduces police response times by alerting them before civilians call 911, the audit found police response to 911 calls was actually more than 90 seconds faster.

A police source who works in a Manhattan precinct said when an alert turns out to be inaccurate, it’s time-consuming to perform a required investigation and file the necessary report.

But, the source noted, when ShotSpotter is accurate, it is extremely accurate.

Lander pushed the NYPD to refuse to renew the contract when it expires in December without a more thorough review of the effectiveness of the system. The department rejected that suggestion, saying it could not conduct such a review prior to renewal, according to the audit.

The NYPD also countered that just because evidence of a shooting is not recovered does not mean a crime did not take place, the audit stated.

The department also argued a police response itself “dissuades” crime even if the alert is not accurate, the report noted.

Lander said the NYPD should make more statistics public on the effectiveness of ShotSpotter, but the department argued the figures could be “misinterpreted.”